1. Field of Invention
The invention relates to a compressor and, in particular, to an electrically driven compressor system for vehicles.
2. Related Art
In general, the compressor system for vehicles is usually driven by the gasoline engine. However, recently due to the soaring oil price and other limited resources will eventually run out, all car makers have committed to the research and development of electrically driven vehicles. It is also an inevitable trend to change the vehicle compressor system into fully electrically powered.
Nevertheless, currently the electrically driven compressor system (such as refrigerators and other appliances) cannot be directly transferred to vehicles because of the following reasons:
The compressor system for home appliances has a chamber at its the bottom for holding refrigerant oil. As the compressor operates, the refrigerant oil is simultaneously sucked up to lubricate internal components of the compressor. Therefore, the compressor system of home appliances must be kept in a still environment in order to avoid the situation where the refrigerant oil cannot be sucked up, resulting in damages to the compressor due to insufficient lubrication. However, there must be vibrations in a running or operating vehicle, compressor systems for household appliances cannot be applicable to vehicles.
Furthermore, the environmental temperature caused by the vehicle in operation is higher. It is likely to cause the compressor motor to overheat and result in performance degradation. The high environmental temperature will also cause circuit damages to the compressor system.